Remelting Process of Rare Earth Magnet Scrap and/or Sludge and Magnet-Forming Alloy and Sintered Rare Earth Magnet

• Main Authors: HIROTA KOICHI, MINOWA TAKEHISA
• Format: Patent
• Language: English; Korean
• Published: 23.01.2003
• Edition: 7
• Subjects: BASIC ELECTRIC ELEMENTS; CHEMISTRY; ELECTRICITY; FERROUS OR NON-FERROUS ALLOYS; INDUCTANCES; MAGNETS; METALLURGY; PRETREATMENT OF RAW MATERIALS; PRODUCTION AND REFINING OF METALS; SELECTION OF MATERIALS FOR THEIR MAGNETIC PROPERTIES; TRANSFORMERS; TREATMENT OF ALLOYS OR NON-FERROUS METALS

PURPOSE: A method for remelting scrap and/or sludge of rare earth magnet, an alloy for magnet and a rare earth sintered magnet are provided to recover the rare earth at a high efficiency and in an increased yield. CONSTITUTION: A method comprises a step of charging a melting furnace crucible with a rare earth-free magnet-constituent metal feed, a step of heating the metal feed for melting into a melt, a step of adding to the melt a rare earth-containing metal feed and 0.1 to 50% by weight based on the metal feeds of the R-Fe-B base rare earth magnet scrap and/or sludge, a step of adding 0.01 to 30% by weight based on the metal feeds of a particulate flux containing a halide of at least one metal selected from among alkali metals, alkaline earth metals and rare earth metals and having an average particle size of 1 to 50μm, and a step of melting the resulting mixture. 본 발명은 희토류 자석 스크랩 및/또는 슬러지를 용해 원료로 하여 고효율로, 또한 용해 수율을 향상시켜서 희토류 원소를 회수할 수 있는 희토류 자석 스크랩 및/또는 슬러지의 재용해 방법, 이 방법으로 얻어지는 희토류 합금 및 희토류 소결 자석을 제공한다. 또한, 본 발명은 플럭스의 비산을 억제하고, 용해로 내의 오염을 억제하여, 희토류 자석 스크랩 및/또는 슬러지를 용해 원료로 하여 고순도의 자석용 합금을 얻을 수 있는 희토류 자석 스크랩 및/또는 슬러지의 재용해 방법, 이 방법으로 얻어지는 희토류 합금 및 희토류 소결 자석을 제공한다.